There is widely used a memory card for storing therein videos, images and music data. The memory card is often used to store data for a host apparatus such as cell phone, personal digital assistance, portable music player and digital camera. It is important for the memory card to have a large storage capacity and additionally to be small in order to be efficiently used in the portable small-sized host apparatus. Further, it is important to improve data transfer speed between the memory card and the host apparatus.
The memory card includes a semiconductor memory chip and a controller chip for controlling a semiconductor memory. A NAND flash memory is used as the semiconductor memory, for example.
SD™ card (to be referred to as SD card below) is known as the memory card. Micro SD™ card (to be referred to as micro SD card below) is present. The micro SD card and the SD card has almost the same operation and performance. However, the micro SD card is smaller in size than the SD card. Like the SD card, various constraints to be complied by products are defined in a specification for the micro SD card. In order to be applicable to all the kinds of products, the micro SD card can be preferably assured in product's reliability and can be efficiently designed and manufactured.